Bottom Line:
Hallucinations are common in psychiatric disorders, and are also experienced by many individuals who are not mentally ill.Using both newly validated visual classification techniques and automated, data-driven methods, hallucinations were associated with specific brain morphology differences in the paracingulate sulcus, a fold in the medial prefrontal cortex, with a 1 cm reduction in sulcal length increasing the likelihood of hallucinations by 19.9%, regardless of the sensory modality in which they were experienced.The findings suggest a specific morphological basis for a pervasive feature of typical and atypical human experience.

ABSTRACTHallucinations are common in psychiatric disorders, and are also experienced by many individuals who are not mentally ill. Here, in 153 participants, we investigate brain structural markers that predict the occurrence of hallucinations by comparing patients with schizophrenia who have experienced hallucinations against patients who have not, matched on a number of demographic and clinical variables. Using both newly validated visual classification techniques and automated, data-driven methods, hallucinations were associated with specific brain morphology differences in the paracingulate sulcus, a fold in the medial prefrontal cortex, with a 1 cm reduction in sulcal length increasing the likelihood of hallucinations by 19.9%, regardless of the sensory modality in which they were experienced. The findings suggest a specific morphological basis for a pervasive feature of typical and atypical human experience.

Mentions:
Consistent with reductions in mPFC cortical folding in hallucinations, grey matter volume was significantly greater in the functionally defined 8-mm sphere mPFC region of interest surrounding the anterior PCS in patients with schizophrenia who experienced hallucinations than in those who did not (x=6, y=54, z=−5; BA 10; Z=2.82; P=0.036 (small volume corrected), Fig. 4). The region identified as significant using this voxel-based method was smaller than the region that emerged in the surface-based gyrification analysis, which may be attributable to the different properties of cortical morphology measured, as well as any of numerous statistical and methodological differences between the two techniques (see Methods section for details). In any event, no significant grey matter volume differences elsewhere in the brain, associated with the occurrence of hallucinations, survived correction for multiple comparisons.

Mentions:
Consistent with reductions in mPFC cortical folding in hallucinations, grey matter volume was significantly greater in the functionally defined 8-mm sphere mPFC region of interest surrounding the anterior PCS in patients with schizophrenia who experienced hallucinations than in those who did not (x=6, y=54, z=−5; BA 10; Z=2.82; P=0.036 (small volume corrected), Fig. 4). The region identified as significant using this voxel-based method was smaller than the region that emerged in the surface-based gyrification analysis, which may be attributable to the different properties of cortical morphology measured, as well as any of numerous statistical and methodological differences between the two techniques (see Methods section for details). In any event, no significant grey matter volume differences elsewhere in the brain, associated with the occurrence of hallucinations, survived correction for multiple comparisons.

Bottom Line:
Hallucinations are common in psychiatric disorders, and are also experienced by many individuals who are not mentally ill.Using both newly validated visual classification techniques and automated, data-driven methods, hallucinations were associated with specific brain morphology differences in the paracingulate sulcus, a fold in the medial prefrontal cortex, with a 1 cm reduction in sulcal length increasing the likelihood of hallucinations by 19.9%, regardless of the sensory modality in which they were experienced.The findings suggest a specific morphological basis for a pervasive feature of typical and atypical human experience.

ABSTRACTHallucinations are common in psychiatric disorders, and are also experienced by many individuals who are not mentally ill. Here, in 153 participants, we investigate brain structural markers that predict the occurrence of hallucinations by comparing patients with schizophrenia who have experienced hallucinations against patients who have not, matched on a number of demographic and clinical variables. Using both newly validated visual classification techniques and automated, data-driven methods, hallucinations were associated with specific brain morphology differences in the paracingulate sulcus, a fold in the medial prefrontal cortex, with a 1 cm reduction in sulcal length increasing the likelihood of hallucinations by 19.9%, regardless of the sensory modality in which they were experienced. The findings suggest a specific morphological basis for a pervasive feature of typical and atypical human experience.